Linear actuator and light system for a truck trailer

ABSTRACT

A trailer includes a front section having a first floor approximately between three and six feet above a street level. A rear section has a second floor approximately between three and six feet above the street level. A horizontally-oriented platform is disposed in the middle section. At least one linear actuator is coupled to the platform and selectively raises and lowers the platform between a lower position at most two feet above the street level and an upper position approximately between three and seven feet above the street level. Warning lights indicate a position and state of motion of the platform.

CROSS-REFERENCED TO RELATED APPLICATIONS

This application claims benefit of U.S. Provisional Application No.62/980,161 filed on Feb. 22, 2020, the disclosure of which is herebyincorporated by reference in its entirety for all purposes.

BACKGROUND

The present invention relates to a trailer, container, or othertransport vehicle. Trailers typically have a floor that is ±49 inchesabove street level for unloading cargo onto a loading dock that is alsoat the same height. A problem is that cargo sometimes needs to beunloaded onto a curb that is less than one foot above street level.Difficulty may be encountered in lowering the cargo from the±49-inch-high trailer floor onto the curb below.

U.S. Pat. No. 3,051,335 (Bartlett) and U.S. Patent Pub. No. 20030206791(Wroblewski) each disclose a trailer elevator wherein a floor section atthe rear door may be lowered. A problem is that the trailer is notsealed when the floor section is lowered, and thus the floor must beraised while hauling cargo, which limits the volume of cargo that may behauled.

SUMMARY

The present invention may include a trailer having a rear door providingaccess to a dock-level floor section that is ±49 inches above streetlevel and a side door providing access to a platform(s) from curb-levelelevations. In-trailer elevators may be provided such that the platformis movable between the curb-level position and a dock-level position inwhich the platform is co-planar with the dock-level floor section. Whenthe platform is raised to the dock-level position, a freight movingdevice, such as a forklift, clamp truck, or pallet jack may enter therear door and drive on the platform in order to access anotherdock-level floor section that is at the front end of the trailer. Theplatform may be in the curb-level position during transport such thatspace is available from the ceiling all the way down to the curb-levelplatform for storing an increased volume of cargo.

The trailer may include a compartment (“belly”) below the ±49-inch-highmain floor of the trailer, between the trailer's landing gear and rearwheels, and extending down to curb height. Thus, the trailer has twodifferent floor heights—a vertically movable platform which serves as afloor at curb level in the belly compartment, and a main floor at thestandard ±49-inch loading dock height both in front of and behind thebelly compartment. A door that also extends down to curb height may bein the sidewall of the trailer to enable unloading of cargo in the bellycompartment onto a curb. The belly compartment is accessible from themain compartment of the trailer. Both the belly compartment and the maincompartment are sealed from the outside ambient environment. The rear ofthe trailer also has a standard ±49-inch-high floor and rear door forloading and unloading onto a loading dock.

Conventional monocoque dry freight vans with standard industryrecognized (±49 inch) floor heights can have different configurations.One such configuration may include standard industry recognized (±49inch) floor heights fore and aft, with a deep center drop section ofvarying heights. Both the belly/center-drop section and the maincompartment are sealed from the ambient environment. In an inventiveembodiment, drop sections may have self-supporting, clear span, verticalmotion platforms that, in one configuration, can be utilized withoutrestriction in standard, widely accepted freight carrying capacities;the secondary configuration, through the use of vertical liftingplatforms, provides the flexibility of additional cargo carryingcapacity with the ability to load and unload standard or bulky itemsthrough the standard height rear entry. Multiple lifting devices may beattached to single or multiple free-span, self-supporting platform(s). Aplatform may be vertically lowered into and raised out of the bellycompartment of the trailer. The platform can be raised to the nominalmain floor height. A locking mechanism may secure the platform,providing support at standard floor height for loading and unloading ofthe front compartment of the trailer with a freight moving device, suchas a forklift, clamp truck, or pallet jack. The platform may be loweredto curb height in the belly compartment for supporting increased cargoduring transport. Longitudinal and lateral stability may be controlledby frictional, magnetic, hydraulic, pneumatic, or mechanical means andutilize guides, rollers, slides, or other components. In one embodiment,the lifting devices are electric powered linear screw-type actuators.Actuation of the free-span platform may be electric, hydraulic,pneumatic, mechanical, or a combination thereof, which may integratescrews, opposing forces, liquids or gasses as methods or componentsproviding motion. One of the lifting devices may be a master and maycontrol and/or send signals to the other lifting devices utilizing anoperator input device located in the interior.

In one embodiment, the invention includes individually-controllable,free-spanning, vertically actuated platforms implemented in a vantrailer that, when loaded and actuated in a downward direction, provideadditional cubic capacity within the trailer, and/or the ability to takefreight from the standard ±49 inch dock/floor height to the lowerlevels, enabling curb height deliveries out of the side of the trailer.

In one embodiment, linear actuators are attached at each of the fourcorners of a platform to raise and lower the platform. The platform maybe lowered into and raised out of the belly compartment of the trailer.The platform can be raised to the ±49-inch main floor height forsupporting a freight moving device, such as a forklift, clamp truck, orpallet jack in loading and unloading the front compartment of thetrailer. The platform may be lowered to curb height in the bellycompartment for supporting cargo during transport. In one embodiment,the linear actuators are screw-type actuators. The actuators may beelectric, hydraulic, or pneumatic, for example. The actuators may all besynchronized with each other. One of the four actuators may be a masterand may control and send signals to the other three actuators.

In one embodiment, a multi-colored light warning system informs a userof the position and/or movement of the platform in the belly compartmentof the trailer. A green color light indicates that the platform isstationary and has been automatically latched at its upper position atthe same vertical level as the main floor of the trailer. Thus, afreight moving device, such as forklift, clamp truck, or pallet jack,may be safely driven onto the platform. A yellow or amber color lightindicates that the platform is in motion. A red light indicates that theplatform is stationary and is not at its upper, locked, and stowedposition. The upper position that enables a freight moving device, suchas a forklift, clamp truck, or pallet jack to traverse the platform maybe referred to herein as a “locked and stowed position”.

The warning system may be comprised of different colors and may haveadditional functions. The lights may be mounted on the platform, orinterior surfaces of the trailer, such as the floor, sidewalls, or roof.

The invention comprises, in one form thereof, a trailer including afront section having a first floor approximately between three and sixfeet above a street level, a middle section, and a rear section having asecond floor approximately between three and six feet above the streetlevel. A horizontally-oriented platform is disposed in the middlesection. At least one linear actuator is coupled to the platform andselectively raises and lowers the platform between a lower position ofone to two feet above street level, otherwise known as curb-level, andan upper position of approximately between three and seven feet abovestreet level.

The invention comprises, in another form thereof, a trailer including aplatform for supporting cargo. At least one linear actuator is coupledto the platform and selectively raises and lowers the platform.

The invention comprises, in yet another form thereof, a trailerincluding a front section having a first floor that is approximatelybetween three and six feet above a street level, a middle section, and arear section having a second floor that is approximately between threeand six feet above the street level. A horizontally-oriented platform isdisposed in the middle section. The platform is selectively raised andlowered between a lower position of one to two feet above street level,otherwise known as curb-level, and an upper position of approximatelybetween three and seven feet above street level. At least onelight-emitting device is disposed within, and is visible within, aninterior of the trailer. The at least one light-emitting device emitslight the color which is dependent upon vertical position and movementof the platform.

BRIEF DESCRIPTION OF THE DRAWINGS

The above mentioned and other features and objects of this invention,and the manner of attaining them, will become more apparent and theinvention itself will be better understood by reference to the followingdescription of an embodiment of the invention taken in conjunction withthe accompanying drawings, wherein:

FIG. 1 is a side view of one embodiment of a trailer of the presentinvention;

FIG. 1a is a rear view of the trailer of FIG. 1;

FIG. 2 is a fragmentary side sectional view of the trailer of FIG. 1aalong line 2-2;

FIG. 3 is a perspective view of one of the elevator assemblies shown inFIG. 2;

FIG. 4 is an enlarged view of area 4 of FIG. 2;

FIG. 5 is an enlarged side view of one of the platforms and associatedlifting mechanisms of FIG. 2.

FIG. 6 is an overhead view of the three platforms and associated liftingmechanisms of FIG. 2.

FIG. 7 is an overhead view of the middle platform and associated liftingmechanisms of FIG. 6.

FIG. 8 is an enlarged overhead view of the righthand side of the middleplatform and associated lifting mechanisms of FIG. 7.

Corresponding reference characters indicate corresponding partsthroughout the several views. Although the drawings representembodiments of the present invention, the drawings are not necessarilyto scale and certain features may be exaggerated in order to betterillustrate and explain the present invention. Although theexemplification set out herein illustrates embodiments of the invention,in several forms, the embodiments disclosed below are not intended to beexhaustive or to be construed as limiting the scope of the invention tothe precise forms disclosed.

DETAILED DESCRIPTION

The embodiments hereinafter disclosed are not intended to be exhaustiveor limit the invention to the precise forms disclosed in the followingdescription. Rather the embodiments are chosen and described so thatothers skilled in the art may utilize its teachings.

Referring to the drawings, wherein like numerals indicate like elements,FIG. 1 illustrates a side view of one embodiment of a trailer 100 of thepresent invention. Trailer 100 includes a front wall 102, a leftsidewall 104, one or two rear doors 106, a roof sheet 108, a forwardmain floor section 110, a rear main floor section 112, and a middlecurb-level floor section 114. The space in trailer 100 above middlecurb-level floor section 114 and below the vertical level of main floorsections 110, 112 may be referred to herein as the “belly” of trailer100. Forward main floor section 110 and rear main floor section 112 mayboth be about 49 inches above a street level 116 to facilitate loadingand unloading of trailer 100 from and onto a standard-height loadingdock. Middle curb-level floor section 114 may be less than one foot, butno more than three feet above street level 116 to facilitate loading andunloading of trailer 100 from and onto a standard-height curb.

A door 118 may be provided in sidewall 104 above middle curb-level floorsection 114. Cargo may be loaded into and out of the belly of trailer100 at curb-height through door 118. Door 118 is shown in a closedposition such that the belly and the remainder of the interior space oftrailer 100 may be enclosed during transport. However, door 118 may bemoved to an open position for loading cargo into and out of the belly oftrailer 100.

FIG. 1a is a rear view of trailer 100. Doors 106 may each swing openabout respective axis 120, 122. Trailer 100 includes a right sidewall136.

FIG. 2 illustrates the middle section of trailer 100 above middlecurb-level floor section 114 along line 2-2 of FIG. 1a . Immediatelyabove middle curb-level floor section 114 are three elevator assemblieseach including a respective one of elevatable platforms 124 a-c whichare aligned from the front to the rear of the middle section of trailer100. Each of platforms 124 a-c may be individually raised or lowered bya respective set of four lifting devices 126. Only two lifting devices126 are visible in FIG. 2 as being associated with each of platforms 124a-c on the lefthand side of each of platforms 124 a-c. Lifting devices126 may include electric, hydraulic, pneumatic and/or mechanicalcomponents, screws, liquids and/or gasses.

Platforms 124 a-b are shown in FIG. 2 in their lowermost positionswherein platforms 124 a-b are closest to middle curb-level floor section114. In contrast, platform 124 c is raised by lifting devices 126 abovemiddle curb-level floor section 114 to a vertical level that is ±49inches above street level 116 such that a top surface of platform 124 cis at the same vertical level as the top surface of rear main floorsection 112. Platform 124 c may be secured at this raised vertical levelby a locking mechanism.

Load bars 134 each have a left end latched onto left sidewall 104 and aright end latched onto an opposing right sidewall 136 such that loadbars 134 may support freight or cargo 138, 140 at uppermost positionswithin trailer 100. Other load bars 142 each have a left end latchedonto left sidewall 104 and a right end latched onto right sidewall 136such that load bars 142 may support freight or cargo 144 at middle orintermediate vertical levels within trailer 100. As shown in FIG. 2,right sidewall 136 has a respective set of three vertical posts 146 a-cassociated with and laterally adjacent each of platforms 124 a-c. Arearmost post 146 c of each set has a set of vertically aligned lights148 that are visible to a user who is inside trailer 100, such as aforklift driver.

FIG. 3 illustrates more completely the forwardmost one of the elevatorassemblies shown in FIG. 2, and the other two elevator assemblies may beidentical to the elevator assembly of FIG. 3. Platform 124 a may belifted and lowered by four lifting devices 126 which are all attached tothe same curb level floor 114. Each lifting device 126 includes astationary body 130 and vertically movable linkage 132. Platform 124 amay be attached to movable linkages 132 such that platform 124 a followsthe up and down movements of movable linkages 132 within the belly oftrailer 100.

The lifting devices may be electric powered linear screw-type actuatorswherein both the stationary bodies and movable linkages are threaded andare threadedly coupled together. Actuation of the free-span platform maybe electric, hydraulic, pneumatic, mechanical, or a combination thereof,which may integrate screws, opposing forces, liquids or gasses asmethods or components providing motion. One of the lifting devices maybe a master and may control and/or send signals to the other liftingdevices utilizing an operator input device located in the interior ofthe trailer.

FIG. 4 is an enlarged view of area 4 of FIG. 2, showing lights 148 moreclearly. Lights 148 may serve as a warning system that informs a user ofthe position and/or movement of the platforms 124 a-c within trailer100. A green color light indicates that the respective platform isstationary and has been latched at its uppermost position at the samevertical level as the main floors 110, 112 of trailer 100. Thus, afreight moving device, such as forklift, clamp truck, or pallet jack,may be safely supported by the platform. A yellow or amber color lightindicates that the respective platform is in motion. A red lightindicates that the respective platform is stationary and is not at itsuppermost, stowed and locked position. Each individual light 148 may becapable of selectively emitting red, yellow, or green light.Alternatively, each individual light 148 may be capable of emitting onlyone color of light.

In another embodiment, a green light indicates that the respectiveplatform as well as any and all platform(s) behind the respectiveplatform is/are stationary and has/have been latched at its/theiruppermost position at the same vertical level as the main floors 110,112 of trailer 100. For example, the light 148 associated with frontmostplatform 124 a is green only when all three platforms 124 a-c arestationary and have been latched at their uppermost position at the samevertical level as the main floors 110, 112 of trailer 100. Thus, aforklift driver sees a green light associated with front platform 124 aonly if it is safe to drive across platforms 124 b-c onto platform 124a. Similarly, the light 148 associated with middle platform 124 b isgreen only when both platforms 124 b-c are stationary and have beenlatched at their uppermost position at the same vertical level as themain floors 110, 112 of trailer 100. Thus, a forklift driver sees agreen light associated with middle platform 124 b only if it is safe todrive across platform 124 c onto platform 124 b. The light 148associated with rear platform 124 c is green only when platform 124 c isstationary and has been latched at its uppermost position at the samevertical level as the main floors 110, 112 of trailer 100.

The light 148 associated with frontmost platform 124 a is yellow onlywhen at least one of platforms 124 a-c is in motion and any platform 124a-c that is not in motion is stationary at its uppermost, locked andstowed position at the same vertical level as the main floors 110, 112of trailer 100. Similarly, the light 148 associated with middle platform124 b is yellow only when at least one of platforms 124 b-c is in motionand any platform 124 b-c that is not in motion is stationary at itsuppermost, locked and stowed position at the same vertical level as themain floors 110, 112 of trailer 100. The light 148 associated with rearplatform 124 c is yellow only when platform 124 c is in motion.

The light 148 associated with frontmost platform 124 a is red only whenat least one of platforms 124 a-c is stationary and is not at itsuppermost, locked and stowed position. The light 148 associated withmiddle platform 124 b is red only when at least one of platforms 124 b-cis stationary and is not at its uppermost, locked and stowed position.The light 148 associated with rear platform 124 c is red only whenplatform 124 c is stationary and is not at its uppermost position.

Signals sent to control lifting devices 126 may be monitored todetermine whether each platform is stationary at its uppermost, lockedand stowed position, is in motion, or is stationary below its uppermost,locked and stowed position. Alternatively, a position sensor (not shown)and/or a motion sensor (not shown) may be associated with each ofplatforms 124 a-c to detect the position and/or state of motion of theplatform. A respective lock sensor (not shown) may be associated witheach of platforms 124 a-c to detect whether the platform has been lockedat its uppermost position.

FIG. 5 illustrates platform 124 c and associated platform liftingdevices 126 in more detail. It is to be understood that these detailsmay also apply to the other platforms 124 a-b. Platform lockingmechanisms 147 lock platform 124 c at the raised vertical level shown inFIGS. 2 and 5. Platform guide roller mechanisms 149 guide the movementof platform 124 c in up and down vertical directions and help tomaintain platform 124 c in a horizontal orientation while in motion.

FIG. 6 illustrates the three platforms 124 a-c and associated liftingmechanisms 126 of FIG. 2. Also visible in FIG. 6 are platform lockingmechanisms 147 and platform guide roller mechanisms 149. Middlecurb-level floor section 114 is visible between the above-mentionedcomponents.

FIG. 7 illustrates the middle platform 124 b and associated liftingmechanisms 126 of FIG. 6. Also visible in FIG. 7 are platform lockingmechanisms 147 and platform guide roller mechanisms 149.

FIG. 8 illustrates the righthand side of the middle platform 124 b andassociated lifting mechanisms 126 of FIG. 7. Also visible in FIG. 8 areplatform locking mechanisms 147 and platform guide roller mechanisms149.

The invention may be applied to a trailer, container, or truck body.Trailers, containers, or truck bodies may be conjunctively referred toherein as “transportation vessels”.

While this invention has been described as having an exemplary design,the present invention may be further modified within the spirit andscope of this disclosure. This application is therefore intended tocover any variations, uses, or adaptations of the invention using itsgeneral principles. Further, this application is intended to cover suchdepartures from the present disclosure as come within known or customarypractice in the art to which this invention pertains.

What is claimed is:
 1. A transportation vessel, comprising: a frontsection having a first floor approximately between three and six feetabove a street level; a middle section; a rear section having a secondfloor approximately between three and six feet above the street level; ahorizontally-oriented platform disposed in the middle section; and atleast one linear actuator coupled to the platform and configured toselectively raise and lower the platform between a lower position of oneto two feet above street level, otherwise known as curb-level, and anupper position of approximately between three and seven feet abovestreet level.
 2. The transportation vessel of claim 1 wherein theplatform includes four corners, the at least one linear actuatorcomprising four linear actuators, each of the four said actuators beingassociated with a respective one of the four corners.
 3. Thetransportation vessel of claim 1 wherein the at least one linearactuator comprises at least one electric powered linear screw-typeactuator.
 4. The transportation vessel of claim 1 wherein the at leastone linear actuator comprises at least one electric, hydraulic orpneumatic linear actuator.
 5. The transportation vessel of claim 1wherein the at least one linear actuator comprises a plurality of linearactuators that are all synchronized with each other.
 6. Thetransportation vessel of claim 1 wherein the at least one linearactuator comprises a plurality of linear actuators, and one of theactuators is a master actuator that controls and sends signals to allother said actuators.
 7. A transportation vessel, comprising: a platformconfigured to support cargo; and at least one linear actuator coupled tothe platform and configured to selectively raise and lower the platform.8. The transportation vessel of claim 7 wherein the platform includesfour corners, the at least one linear actuator comprising four linearactuators, each said actuator being associated with a respective one ofthe four corners.
 9. The transportation vessel of claim 7 wherein the atleast one linear actuator comprises at least one electric powered linearscrew-type actuator.
 10. The transportation vessel of claim 7 whereinthe at least one linear actuator comprises at least one electric,hydraulic or pneumatic linear actuator.
 11. The transportation vessel ofclaim 7 wherein the at least one linear actuator comprises a pluralityof linear actuators that are all synchronized with each other.
 12. Thetransportation vessel of claim 7 wherein the at least one linearactuator comprises a plurality of linear actuators, and one of theactuators is a master actuator that controls and sends signals to allother said actuators.
 13. The transportation vessel of claim 7 whereinthe transportation vessel comprises a motor vehicle hauler, and theplatform is configured to support a motor vehicle.
 14. Thetransportation vessel of claim 13 wherein the at least one linearactuator is configured to selectively move the platform into ahorizontal orientation and a non-horizontal orientation.
 15. Atransportation vessel, comprising: a front section having a first floorapproximately between three and six feet above a street level; a middlesection; a rear section having a second floor approximately betweenthree and six feet above the street level; a horizontally-orientedplatform disposed in the middle section, the platform being configuredto be selectively raised and lowered between a lower position of one totwo feet above street level, otherwise known as curb-level, and an upperposition of approximately between three and seven feet above streetlevel; and at least one light-emitting device disposed and visiblewithin an interior of the transportation vessel, the at least onelight-emitting device being configured to emit light the color which isdependent upon vertical position and movement of the platform.
 16. Thetransportation vessel of claim 15 wherein emission of a first color oflight by the at least one light-emitting device indicates that theplatform is stationary and is at its uppermost, locked and stowedposition at a same vertical level as the first floor and/or the thirdfloor, emission of a second color of light by the at least onelight-emitting device indicates that the platform is in motion, andemission of a third color of light by the at least one light-emittingdevice indicates that the platform is stationary and is not at itsuppermost, locked and stowed position.
 17. The transportation vessel ofclaim 15 wherein the horizontally-oriented platform comprises afrontmost horizontally-oriented platform disposed in a front of themiddle section, the at least one light-emitting device comprising afirst light-emitting device configured to emit light the color which isdependent upon movement and a vertical level of only the frontmosthorizontally-oriented platform, the transportation vessel furthercomprising: a middle horizontally-oriented platform disposed in a middleof the middle section, the middle horizontally-oriented platform beingconfigured to be selectively raised and lowered above the second floor;a second light-emitting device configured to emit light the color whichis dependent upon movement and a vertical level of only the middlehorizontally-oriented platform; a rearmost horizontally-orientedplatform disposed in a rear of the middle section, the rearmosthorizontally-oriented platform being configured to be selectively raisedand lowered above the second floor; and a third light-emitting devicebeing configured to emit light the color which is dependent uponmovement and a vertical level of each of the platforms.
 18. Thetransportation vessel of claim 15 wherein the horizontally-orientedplatform comprises a frontmost horizontally-oriented platform disposedin a front of the middle section, the transportation vessel furthercomprising: a middle horizontally-oriented platform disposed in a middleof the middle section, the middle horizontally-oriented platform beingconfigured to be selectively raised and lowered above the second floor;and a rearmost horizontally-oriented platform disposed in a rear of themiddle section, the rearmost horizontally-oriented platform beingconfigured to be selectively raised and lowered above the second floor,the at least one light-emitting device being configured to emit lightthe color which is dependent upon movement and a vertical level of eachof the platforms.
 19. The transportation vessel of claim 18 whereinemission of a first color of light by the at least one light-emittingdevice indicates that each of the three platforms is stationary and isat its uppermost, locked and stowed position at a same vertical level asthe first floor and/or the third floor, emission of a second color oflight by the at least one light-emitting device indicates that at leastone of the three platforms is in motion and each of the three platformsis either in motion or is at its uppermost, locked and stowed positionat a same vertical level as the first floor and/or the third floor, andemission of a third color of light by the at least one light-emittingdevice indicates that at least one of the three platforms is stationaryand is not at its uppermost, locked and stowed position.
 20. Thetransportation vessel of claim 19 wherein the at least onelight-emitting device comprises a first light-emitting device, thetransportation vessel further comprising a second light-emitting devicedisposed and visible within an interior of the transportation vessel,the second light-emitting device being configured to emit light thecolor which is dependent upon movement and a vertical level of themiddle horizontally-oriented platform and the rearmosthorizontally-oriented platform, wherein emission of the first color oflight by the second light-emitting device indicates that both the middlehorizontally-oriented platform and the rearmost horizontally-orientedplatform is stationary and is at its uppermost, locked and stowedposition at a same vertical level as the first floor and/or the thirdfloor, emission of the second color of light by the secondlight-emitting device indicates that at least one of the middlehorizontally-oriented platform and the rearmost horizontally-orientedplatform is in motion and both the middle horizontally-oriented platformand the rearmost horizontally-oriented platform is either in motion oris at its uppermost, locked and stowed position at a same vertical levelas the first floor and/or the third floor, and emission of the thirdcolor of light by the second light-emitting device indicates that atleast one of the middle horizontally-oriented platform and the rearmosthorizontally-oriented platform is stationary and is not at itsuppermost, locked and stowed position.